Methods for defining and marking tissue

ABSTRACT

In order to later identify the location of a biopsy or surgery, various means and methods for permanently and non-surgically marking selected tissue in the human body are used. Later visualization of the markers is readily accomplished using state-of-the-art imaging systems.

BACKGROUND OF THE INVENTION

[0001] This invention relates to methods and devices for marking anddefining particular locations in human tissue, and more particularlyrelates to methods and devices for permanently defining the location andmargins of lesions detected in a human breast.

[0002] It is desirable and often necessary to perform procedures fordetecting, sampling, and testing lesions and other abnormalities in thetissue of humans and other animals, particularly in the diagnosis andtreatment of patients with cancerous tumors, pre-malignant conditionsand other diseases or disorders. Typically, in the case of cancer, whena physician establishes by means of known procedures (i.e. palpation,x-ray, MRI, or ultrasound imaging) that suspicious circumstances exist,a biopsy is performed to determine whether the cells are cancerous.Biopsy may be an open or percutaneous technique. Open biopsy removes theentire mass (excisional biopsy) or a part of the mass (incisionalbiopsy). Percutaneous biopsy on the other hand is usually done with aneedle-like instrument and may be either a fine needle aspiration (FNA)or a core biopsy. In FNA biopsy, very small needles are used to obtainindividual cells or clusters of cells for cytologic examination. Thecells may be prepared such as in a Papanicolaou (Pap) smear. In corebiopsy, as the term suggests, a core or fragment of tissue is obtainedfor histologic examination which may be done via a frozen section orparaffin section. The chief difference between FNA and core biopsy isthe size of the tissue sample taken. A real time or near real timeimaging system having stereoscopic capabilities, such as thestereotactic guidance system described in U.S. Pat. No. 5,240,011, isemployed to guide the extraction instrument to the lesion. Advantageousmethods and devices for performing core biopsies are described in theassignee's co-pending patent application Ser. No. 08/217,246, filed onMar. 24, 1994, and herein incorporated by reference.

[0003] Depending upon the procedure being performed, it is sometimesdesirable to completely remove suspicious lesions for evaluation, whilein other instances it may be desirable to remove only a sample from thelesion. In the former case, a major problem is the ability to define themargins of the lesions at all times during the extraction process.Visibility of the lesion by the imaging system may be hampered becauseof the distortion created by the extraction process itself as well asassociated bleeding in the surrounding tissues. Although the lesion isremoved and all fluids are continuously aspirated from the extractionsite, it is likely that the process will “cloud” the lesion, thusimpairing exact recognition of its margins. This makes it difficult toensure that the entire lesion will be removed.

[0004] Often, the lesion is merely a calcification derived from deadabnormal tissue, which may be cancerous or pre-cancerous, and it isdesirable to remove only a sample of the lesion, rather than the entirelesion, to evaluate it. This is because such a lesion actually serves tomark or define the location of adjacent abnormal tissue, so thephysician does not wish to remove the entire lesion and thereby lose acritical means for later re-locating the affected tissue. One of thebenefits to the patient from core biopsy is that the mass of the tissuetaken is small. However, oftentimes, either inadvertently or because thelesion is too small, the entire lesion is removed for evaluation, eventhough it is desired to remove only a portion. Then, if subsequentanalysis indicates the tissue to be malignant (malignant tissue requiresremoval, days or weeks later, of tissue around the immediate site of theoriginal biopsy), it is difficult for the physician to determine theprecise location of the lesion, in order to perform necessary additionalprocedures on adjacent potentially cancerous tissue. Additionally, evenif the lesion is found to be benign, there will be no evidence of itslocation during future examinations, to mark the location of thepreviously removed calcification so that the affected tissue may becarefully monitored for future reoccurrences.

[0005] Thus, it would be of considerable benefit to be able topermanently mark the location or margins of such a lesion prior to orimmediately after removing or sampling same. Marking prior to removalwould help to ensure that the entire lesion is excised, if desired.Alternatively, if the lesion were inadvertently removed in its entirety,marking the biopsy site immediately after the procedure would enablereestablishment of its location for future identification.

[0006] A number of procedures and devices for marking and locatingparticular tissue locations are known in the prior art. For example,location wire guides, such as that described in U.S. Pat. No. 5,221,269to Miller et al, are well known for locating lesions, particularly inthe breast. The device described by Miller comprises a tubularintroducer needle and an attached wire guide, which has at its distalend a helical coil configuration for locking into position about thetargeted lesion. The needle is introduced into the breast and guided tothe lesion site by an imaging system of a known type, for example,x-ray, ultrasound, or magnetic resonance imaging (MRI), at which timethe helical coil at the distal end is deployed about the lesion. Then,the needle may be removed from the wire guide, which remains in a lockedposition distally about the lesion for guiding a surgeon down the wireto the lesion site during subsequent surgery. While such a locationsystem is effective, it is obviously intended and designed to be onlytemporary, and is removed once the surgery or other procedure has beencompleted.

[0007] Other devices are known for marking external regions of apatient's skin. For example, U.S. Pat. No. 5,192,270 to Carswell, Jr.discloses a syringe which dispenses a colorant to give a visualindication on the surface of the skin of the point at which an injectionhas or will be given. Similarly, U.S. Pat. No. 5,147,307 to Gluckdiscloses a device which has patterning elements for impressing atemporary mark in a patient's skin, for guiding the location of aninjection or the like. It is also known to tape or otherwise adhere asmall metallic marker, e.g. a 3 millimeter diameter lead sphere, on theskin of a human breast in order to delineate the location of skincalcifications (see Horner et al, The Geographic Cluster ofMicrocalcifications of the Beast, Surgery, Gynecology, & Obstetrics,December 1985). Obviously, however, none of these approaches are usefulfor marking and delineating internal tissue abnormalities, such aslesions or tumors.

[0008] Still another approach for marking potential lesions and tumorsof the breast is described in U.S. Pat. No. 4,080,959. In the describedprocedure, the skin of the portion of the body to be evaluated, such asthe breasts, is coated with a heat sensitive color-responsive chemical,after which that portion of the body is heated with penetratingradiation such as diathermy. Then, the coated body portion is scannedfor color changes which would indicate hot spots beneath the skinsurface. These so-called hot spots may represent a tumor or lesion,which does not dissipate heat as rapidly because of its relatively poorblood circulation (about {fraction (1/20)} of the blood flow throughnormal body tissue). This method, of course, functions as a temporarydiagnostic tool, rather than a permanent means for delineating thelocation of a tumor or lesion.

[0009] A method of identifying and treating abnormal neoplastic tissueor pathogens within the body is described in U.S. Pat. No. 4,649,151 toDougherty et al. In this method, a tumor-selective photosensitizing drugis introduced into a patients body, where it is cleared from normaltissue faster than it is cleared from abnormal tissue. After the drughas cleared normal tissue but before it has cleared abnormal neoplastictissue, the abnormal neoplastic tissue may be located by theluminescence of the drug within the abnormal tissue. The fluorescencemay be observed with low intensity light, some of which is within thedrugs absorbance spectrum or higher intensity light, a portion of whichis not in the drugs absorbance spectrum. Once detected, the tissue maybe destroyed by further application of higher intensity light having afrequency within the absorbance spectrum of the drug. Of course, thismethod also is only a temporary means for marking the abnormal tissue,since eventually the drug will clear from even the abnormal tissue.Additionally, once the abnormal tissue has been destroyed duringtreatment, the marker is destroyed as well.

[0010] It is also known to employ biocompatible dyes or stains to markbreast lesions. First, a syringe containing the colorant is guided to adetected lesion, using an imaging system. Later, during the extractionprocedure, the surgeon harvests a tissue sample from the stained tissue.However, while such staining techniques can be effective, it isdifficult to precisely localize the stain. Also, the stains aredifficult to detect fluoroscopically and may not always be permanent.

[0011] Additionally, it is known to implant markers directly into apatients body using invasive surgical techniques. For example, during acoronary artery bypass graft (CABG), which of course constitutes openheart surgery, it is common practice to surgically apply one or moremetallic rings to the aorta at the site of the graft. This enables apractitioner to later return to the site of the graft by identifying therings, for evaluative purposes. It is also common practice to mark asurgical site with staples, vascular clips, and the like, for thepurpose of future evaluation of the site.

[0012] A technique has been described for the study of pharyngealswallowing in dogs, which involves permanently implanting steel markerbeads in the submucosa of the pharynx (S. S. Kramer et al, A PermanentRadiopaque Marker Technique for the Study of Pharyngeal Swallowing inDogs, Dysphagia, Vol. 1, pp. 163-167, 1987). The article posits that theradiographic study of these marker beads during swallowing, on manyoccasions over a substantial period of time, provides a betterunderstanding of the pharyngeal phase of degluitition in humans. In thedescribed technique, the beads were deposited using a metal needlecannula having an internal diameter slightly smaller than the beads tobe implanted. When suction was applied to the cannula, the bead satfirmly on the tip. Once the ball-tipped cannula was inserted throughtissue, the suction was broken, thereby releasing the bead, and thecannula withdrawn.

[0013] Of course, this technique was not adapted or intended to markspecific tissue sites, but rather to mark an entire region or structureof the body in order to evaluate anatomical movements (i.e. swallowingmotions). It also was not intended for use in humans.

[0014] Accordingly, what is needed is a method and device fornon-surgically implanting potentially permanent markers at the situs ofa lesion or other abnormal tissue, for the purpose of defining themargins of a lesion before it is removed and/or to establish itslocation after it has been removed. The markers should be easy to deployand easily detected using state of the art imaging techniques.

SUMMARY OF THE INVENTION

[0015] This invention solves the problems noted above by providing animplantable device which is particularly adapted to mark the location ofa biopsy or surgery for the purpose of identification. The device isremotely delivered, preferably percutaneously. Visualization of themarker is readily accomplished using various state of the art imagingsystems. Using the invention, it is possible to permanently mark thelocation or margins of a lesion or other tissue site, prior to removingor sampling same. The markers function to provide evidence of thelocation of the lesion after the procedure is completed, for referenceduring future examinations or procedures.

[0016] More particularly, a device is provided for marking tissue withina human body to identify a selected location for a diagnostic ortherapeutic procedure. The device comprises a marker element and anapparatus for remotely delivering the marker element from outside thehuman body to the selected tissue location. Since, with remote delivery(e.g. percutaneously) direct visual access is not possible, an aidedvisualization device is used, such as an imaging system, an endoscope,or the like. Deployment of the marker element is such that it becomesimplanted in the tissue.

[0017] The delivery apparatus preferably includes a member, which maycomprise a tube, such as a needle, cannula, or trocar, of any known typefor delivering medications, surgical equipment, or other items to theinterior of a patient's body. The member may also be the body of anoptical instrument such as an endoscope, laparoscope, or arthroscope. Inthe preferred embodiment, a biopsy needle or gun, such as is often usedto extract tissue for examination in a biopsy procedure, is used inconjunction with the marking device, comprising a portion of thedelivery apparatus, in order to provide a means for entering thepatient's body and positioning the marker element at the selected tissuelocation. However, in other embodiments, the marking device is selfcontained, having a means itself for obtaining entry to the body, andbeing guided by a commercially available guidance system, such as astereotactic guidance system.

[0018] The aforementioned member or tube, which typically comprises acannula or needle having a lumen, has a distal end portion or region anda proximal end portion or region, and is adapted to extend through thebody. The distal region is adapted to retain and deploy the markerelement and the proximal region is linked to the distal region, so thatpredetermined marker deployment functions may be communicated from theproximal region to the distal region. In some embodiments, thesedeployment functions are communicated by means of the marker elementsthemselves travelling through the lumen for deployment from the distalregion. In other embodiments, an actuator extends axially through thelumen to communicate deployment functions to the marker element held onor by the distal region. The apparatus is preferably guided to theselected tissue location, i.e. the site of the detected lesion or otherabnormality, using a stereotactic guidance system or similar imagingsystem.

[0019] Several alternative embodiments of the marking device aredisclosed. In one embodiment, the distal region of the tube includes aforming die, which is adapted to form each marker element into apredetermined shape, preferably a helix, as the marker element isdeployed from the lumen. In a number of alternative embodiments, amechanism, such as a mandrel, is used to push the marker elementsthrough the tube. The marker elements may comprise a pre-formed springhaving a predetermined shape, which is compressed into a linear positionwithin the tube lumen. Upon deployment from the lumen, the spring isadapted to expand and assume its predetermined shape to such an extentthat the energy of its expansion is sufficient to implant the markerelement into the tissue at the selected tissue location. In someembodiments, implantation is accomplished because the marker elementshave a plurality of attachment elements, each having a tip end(sometimes sharpened) which expands outwardly with sufficient energy toembed and anchor itself into the tissue at the selected tissue location.In other embodiments, the marker element has blunt, rather thansharpened edges, but is adapted to expand sufficiently upon exiting fromthe tube that its edges press radially against the selected tissue,thereby wedging and implanting the marker element.

[0020] In yet another embodiment of the invention, the tube lumen isadapted to receive a deployment actuator connector, or center wire,which extends axially through the lumen. The connector includes a distalportion which extends distally of the tube and a proximal portion whichextends proximally of the tube. The proximal portion is attached to adeployment actuator, such as a pull ring, while the distal portion isattached to the marker element. On the connector, proximal to the distalportion, is a predetermined failure point which is adapted to be theweak point on the connector by failing first under tension. Inoperation, once the tube distal region has been positioned at theselected tissue location, the deployment actuator is actuated in aproximal direction to pull the marker element against the distal regionof the tube. The tube distal region thus functions as a forming die tocause the marker element to bend until it abuts the tube distal regionat its junction with the distal portion of the connector, such that themarker element is reconfigured to a desired shape. The proximal portionof the connector is adapted to be severed from the distal portion at thepredetermined failure point upon the application of continued tension onthe deployment actuator after abutment of the marker element against thetube distal region, thereby releasing and implanting the marker element.

[0021] Another important feature of the invention is the ability toutilize marker elements having a plurality of shapes. In someembodiments, these shapes may be created merely by utilizing differentsized material stock or different cross sections. This shape diversitypermits the adoption of a system wherein each shape denotes a differentselected tissue location or event.

[0022] In a preferred embodiment of the invention, the device is adaptedto be employed in combination with a medical instrument which transportsthe device to the selected tissue location responsive to positionalcontrol by a guidance system. The medical instrument preferably draws avacuum to isolate and retain tissue at the selected location in a tissuereceiving port. The marking device is adapted to deploy the markerelement into the retained tissue.

[0023] In another aspect of the invention, a marker element is providedfor marking tissue within a human body to identify a selected locationfor a diagnostic or therapeutic procedure. The marker element, which ispreferably comprised of a biocompatible, implantable, and substantiallyradiopaque material, is adapted to be deployed to the selected tissuelocation percutaneously by a delivery instrument, so as to becomeimplanted in the tissue.

[0024] A number of different marker element configurations and materialsmay be employed. Materials may include stainless steel, titanium, andthe like, as well as non-metallic materials, such as polymers, salts,and ceramics, for example. In some embodiments, the marker element mayactually be formed into a desired shape by a forming die in the deliveryinstrument, while in other embodiments, it may comprise a spring whichradially expands upon exit from the delivery instrument to embed itselfin the tissue.

[0025] In yet another aspect of the invention, a method for permanentlymarking tissue in a human body to identify a selected location for adiagnostic or therapeutic procedure is disclosed, which comprisesactuating a delivery instrument, having a tube with a distal region, toa position wherein the tube extends through the human body and thedistal region is at the selected location. A marker element is thendeployed from the tube distal region to the selected tissue location sothat it becomes anchored in the tissue.

[0026] These and other aspects and advantages of the present inventionare set forth in the following detailed description and claims,particularly when considered in conjunction with the accompanyingdrawings in which like parts bear like reference numerals.

BRIEF DESCRIPTION OF THE DRAWING

[0027]FIG. 1 is a cross-sectional view of a biopsy instrument embodimentas described in co-pending patent application Ser. No. 08/217,246,configured to be utilized as a preferred instrument for use inconjunction with the inventive tissue marking device;

[0028]FIGS. 2 and 3 are cross-sectional views illustrating thesequential steps in the operation of the biopsy instrument embodimentneeded to capture tissue targeted for marking;

[0029]FIG. 4 is a cross-sectional view of one embodiment of a tissuemarking device constructed in accordance with the principles of theinvention, illustrating the device in a first position in preparationfor delivering a marker to tissue targeted for marking;

[0030]FIGS. 5, 6, 7, and 8 are cross-sectional views similar to FIG. 4,illustrating sequentially the delivery of a marker to the targetedtissue;

[0031]FIGS. 9, 10, and 11 are schematic cross-sectional views of analternative embodiment of a tissue marking device constructed inaccordance with the principles of the invention, illustratingsequentially the delivery of a marker to the targeted tissue;

[0032]FIG. 12 is a schematic cross-sectional view illustrating a thirdalternative embodiment of a tissue marking device constructed inaccordance with the principles of the invention;

[0033]FIG. 13 is a schematic cross-sectional view illustrating a fourthalternative embodiment of a tissue marking device constructed inaccordance with the principles of the invention;

[0034]FIG. 14 is a schematic cross-sectional view illustrating a fifthalternative embodiment of a tissue marking device constructed inaccordance with the principles of the invention;

[0035]FIG. 15 is a schematic cross-section view illustrating a sixthalternative embodiment of a tissue marking device constructed inaccordance with the principles of the invention;

[0036]FIG. 16 is a schematic cross-sectional view illustrating a seventhalternative embodiment of a tissue marking device constructed inaccordance with the principles of the invention;

[0037]FIG. 17 is a front elevation view of an alternative marker elementembodiment;

[0038]FIG. 18 is a perspective view of another alternative markerelement embodiment;

[0039]FIG. 19 is a front elevation view of yet another alternativemarker element embodiment; and

[0040]FIG. 20 is a front elevation view of still another alternativemarker element embodiment.

DETAILED DESCRIPTION OF THE INVENTION

[0041] Now with more particular reference to the drawings, FIGS. 4-8illustrate sequentially the deposit of a marker into a desired tissuelocation, utilizing a preferred embodiment of the invention.Specifically, the marking instrument 10 comprises a marker element 12which includes an umbrella end comprising a pair of attachment membersor wings 14 and 16, and a center wire 18. All three wires 14, 16 and 18are joined at the distal end 20 of the center wire 18, preferably bywelding. At the proximal end 22 of the center wire is a deploymentactuator or pull ring 24, which is preferably attached by welding orbrazing.

[0042] To place the marker element 12 at a desired location, a biopsyneedle or gun is preferably used, though other known delivery meanscould be used as well. For example, the stand-mounted biopsy instrumentdescribed in U.S. patent application Ser. No. 08/217,246, previouslyincorporated by reference into this application, is a preferredinstrument for introducing the marker element into the body of apatient. One embodiment of such an instrument 26 is partiallyillustrated in FIGS. 1-3. The biopsy instrument 26 includes a housing28. A hollow outer piercing needle 38 is attached to the housing 28 atlocation 34. A distal end of the hollow outer piercing needle 38includes a point 40. Hollow outer piercing needle 38 also includes atissue receiving port or bowl 42 (FIGS. 2 and 3). A cannular innercutter 44 is movably positioned coaxially within the hollow outerpiercing needle 38 and housing 28. A vacuum line 46 supplies vacuum toports 50 in the bottom of the receiving bowl 42.

[0043] Operation of the biopsy instrument to facilitate the placement ofa tissue marker is illustrated sequentially in FIGS. 1-3. FIG. 1illustrates the distal end point 40 of the hollow outer piercing needle38 in position to pierce a target tissue 51. The initial position of thepoint 40 with respect to the tissue area being marked is determined bythe overall position of the biopsy instrument with respect to thepatient. For example, the entire biopsy instrument may be mounted on acommercially available stereotactic guidance system (not shown) commonlyused in the medical field for accurate positioning of a variety ofmedical devices with respect to a patient. A detailed description ofsuch a motorized biopsy needle positioner, i.e. stereotactic guidancesystem, is given in U.S. Pat. No. 5,240,011, issued on Aug. 31, 1993 toMichael Assa, which is hereby incorporated herein by reference. Thesuspect lesion within tissue 51 is to be targeted and marked accordingto the instructions provided with the stereotactic guidance system. Asshown in FIG. 1, the stereotactic guidance system has positioned thebiopsy instrument 26 such that the distal end point 40 is immediatelyadjacent to the surface of the tissue 51. Once the point 40 is adjacentthe specific lesion to be marked, the needle 38 is fired into the lesionsuch that the point 40 traverses through the lesion, thereby placing thetissue receiving bowl 42 in the center of the lesion.

[0044] As shown in FIG. 2, after the hollow outer piercing needle 38 hasbeen positioned at the precise location within the tissue 51 at which itis desired to mark tissue, the cutter 44 is moved proximally of thehousing 28 to provide an entry access for the tissue marker deliverysystem.

[0045] As shown in FIG. 3, a vacuum source attached to vacuum line 46 isactuated, thereby generating a region of low pressure at the vacuumports 50 to facilitate the prolapse of tissue 51 a immediately adjacentto the tissue receiving port 42 into the hollow interior of hollow outerpiercing needle 38.

[0046] Now again referring to FIGS. 4-8, the marking instrument 10includes a tube 54. The center wire 18 runs axially through a lumen 56of the tube 54, with the pull ring 24 being attached to the proximal endof the center wire 18, proximally of the tube 54. The distal end 20 ofthe center wire extends distally of the tube 54 and is joined toattachment members 14 and 16, as described above.

[0047] In operation, the tube 54 of the marking instrument is insertedinto the patients body in the direction of the arrow 58, as shown inFIG. 4, until the distal end 20 of the center wire 18 approaches thedesired location, adjacent to or in the abnormal tissue or lesion.Because direct visual access to the targeted tissue is impossible, anaided visualization device, such as the stereotactic guidance systemdescribed above, is used to guide the distal portion of the markinginstrument to the targeted tissue. Then, if the biopsy instrument shownin FIGS. 1-3 is utilized to deploy the markers, the targeted tissue 51 a(FIG. 5) is vacuumed into the tissue receiving port 42. Referringparticularly to FIG. 5, once the distal end 20 of the center wirereaches the targeted, vacuumed tissue, the ring 24 is pulled away fromthe tissue in the direction of the arrow 60. This action deploys themarker attachment members 14 and 16 as they are forced into a die formedin the tip 62 of the tube. This die may take any desired form, dependingupon the desired deployed configuration of the attachment members 14,16.

[0048] With reference to FIG. 6, tension continues to be applied to thering 24, in the direction shown by the arrow 64, until the distal end ofthe marker is fully deployed. Forcing the attachment members into thedie 62 causes them to extend outwardly, as illustrated, into the tissue.Their outward energy anchors the marker element 12 in the tissue forpermanent implantation. The tips 66 and 68 of the attachment members maybe configured to be less traumatic as an implant, or may alternativelybe sharpened to provide a more secure grip. At full deployment, thewidth of the umbrella end of the marker element is preferably about0.035 to 0.045 inches, though other sizes may be utilized within thescope of the invention.

[0049] Now referring to FIG. 7, even after the attachment members 14 and16 have been fully deployed, the pull ring 24 is pulled to furtherincrease tension in the direction of the arrow 70, until the center wire18 is sheared at a point of weakness or detent 72 (see FIGS. 4-6) whichis established in the center wire 18 proximally of the tip 20. Oncefailure has occurred, the pull ring 24 and the proximal portion 18′ ofthe center wire may be discarded as they are severed from the markerelement 12 and remaining distal portion 18″ of the center wire.

[0050] Finally, with reference to FIG. 8, to finish placing the markerelement 12, the tube 54 is withdrawn in the direction of the arrow 74,as illustrated. The marker element is thereby permanently secured tolocate the lesion site for future examination by known imaging methods.

[0051] In the preferred embodiment, the marker element 12 is fabricatedof stainless steel. However, many other biocompatible, radiopaque,implantable materials may be used for the marker element 12 as well,including, for example, titanium, tantalum, or nickel-titanium alloys.Additionally, while a 3-pronged umbrella end is shown and described, anynumber of prongs may be used, if desired.

[0052] While it is preferred that the marker element 12 be deployedusing the biopsy instrument described and shown in FIGS. 1-3, anyinstrument capable of delivering the element percutaneously may beutilized. Such instruments, for example, may include the hand-heldbiopsy gun described in U.S. Pat. No. Re. 34,056, entitled “TISSUESAMPLING DEVICE” and issued to Lindgren et al. All of these types ofinstruments include a tube (typically a cannula or needle) which isadapted to enter the body, and would be capable of delivering the markerelement. It is also within the scope of the invention to deliver themarker element through any tube which has access to the body or usingoptical medical instruments, such as endoscopes, arthroscopes, orlaparoscopes, in which case the marker element is delivered to thedesired tissue site from outside the body of the patient, through thebody of the instrument.

[0053] Now with reference to FIGS. 9-11, an alternative embodiment of amarking instrument 10 a is shown, which is identical to the instrument10 in all respects not shown or described herein. Portions of theinstrument 10 a corresponding to portions of the instrument 10 aredesignated by corresponding reference numerals followed by the letter a.

[0054] The FIG. 9 embodiment is substantially similar to the FIG. 4embodiment, in that the marking instrument includes a tube 54 a whichhas a lumen 56 a, and may utilize a cannula, needle, or imaginginstrument (i.e. endoscope, laparoscope, or the like) for access to adelivery site within the body and to aid in delivery. Again, as is thecase for all succeeding embodiments, it is preferred that the tube 54 autilize the hollow outer piercing needle 38 of the biopsy instrumentshown in FIGS. 1-8, though any other instrument which is capable ofdelivering a marker percutaneously or through a body orifice from alocation outside the patients body may be utilized. A center wire 18 aruns longitudinally through the lumen 56 a. At the proximal end of thecenter wire 18 a is a deployment actuator or pull ring 24 a. At thedistal end of the center wire is the marker element 12 a.

[0055] A primary difference between the FIG. 4 and FIG. 9 embodiments isthat the FIG. 9 marker element 12 a is preferably a generally “U” shapedelement resembling a surgical ligating clip, having tips 66 a and 68 a,which is captured by the distal looped end 20 a of the twisted centerwire. In operation, once the tips 66 a and 68 a of the marking element12 a reach the targeted tissue, the ring 24 a is pulled rightwardly inthe direction of the arrow 76 (FIG. 10). This action retracts the baseportion 78 of the marker element 12 a into a forming recess 80 (FIG. 9),wherein the recessed tube wall 82 forces prongs 86 and 88 together untiltips 66 a and 68 a of the prongs 86 and 88, respectively, contact ornearly contact one another (FIG. 10). At this point, increasing tensionapplied to the pull ring 24 a causes the wire 18 a to fail at a point ofweakness or detent (not shown) provided in the center wire at or nearits tip end 20 a, thereby releasing the marker into the target tissue,as illustrated in FIG. 11.

[0056] Referring now to FIG. 12, a second alternative embodiment of amarking instrument 10 b is shown, which is identical to the instrument10 in all respects not shown or described herein. Portions of theinstrument 10 b corresponding to portions of the instrument 10 aredesignated by corresponding reference numerals followed by the letter b.

[0057] The FIG. 12 embodiment is substantially similar to the FIG. 4embodiment, in that the marking instrument includes a tube 54 b whichhas a lumen 56 b, and may utilize a cannula, needle, or imaginginstrument (i.e. endoscope, laparoscope, or the like) for access todelivery site within the body and to aid in delivery.

[0058] There are two primary differences between the embodiments ofFIGS. 4 & 9 and that of FIG. 12. First, in the FIG. 12 embodiment, aplurality of marker elements 12 b (two are shown, though any number maybe employed) may be preloaded into the tube 54 b, each comprising apre-formed spring which is deployed through the tube's distal region 90in an axial direction. Second, the nature of the deployment mechanismutilizes a compressive rather than tensile force. It may further benoted that, though end deployment of the marker elements in the FIG. 12embodiment is illustrated, they may be similarly deployed radiallythrough a side port (not shown) in tube 54 b, or at any other angle, toaccommodate delivery through an existing instrument (i.e. cannula,needle, endoscope, laparoscope, or the like). In being deployedradially, the distal region 90 is not used for passage of the markerelement and could be utilized to house a piercing element (not shown)similar to that shown in FIGS. 1-3. Armed with the piercing element,this marker delivery system would not be dependent on a positioningsystem as described in FIGS. 1-3 for placement at the tissue site andcould be used alone in conjunction with a commercially availablestereotactic or other guidance system. This concept may be applied toall subsequent embodiments except that illustrated in FIG. 16.

[0059] Still with reference to FIG. 12, each marker element or spring 12b preferably includes a center coil 92 from which a pair of attachmentmembers 94 and 96 extend, and is adapted to automatically attach itselfto the target tissue by utilizing its own stored energy. Thus, inoperation, each spring 12 b is held in a compressed position within thetube 54 b. When it is desired to deploy the marker, a mandrel 98 ispreferably utilized to push the spring 12 b through the center lumen 56b and out through the distal open end 90 of the tube. Once the springexits the tube, stored energy causes the attachment members 94 and 96 toexpand outwardly, as shown. As this expansion occurs, the tips 102 and104 of the attachment members 94 and 96, respectively, anchor themselvesinto the tissue to permanently secure the marker element in the desiredlocation. As with the FIG. 4 embodiment, the tips 102 and 104 may beblunt to be less traumatic as an implant, or may alternatively besharpened or barbed to provide a more secure grip. Once a spring hasbeen deployed, the instrument may be repositioned to the next desiredlocation for the immediate deployment of another marker until the supplyin the tube 54 b is exhausted, eliminating the need to remove andre-load the marking instrument 10 b between each deployment.

[0060] Again in this embodiment, the spring 12 b may be fabricated ofany known biocompatible, implantable, radiopaque material, thoughstainless steel is preferred. Additionally, the forces required todeploy the attachment members on the spring may be customize by varyingthe spring filar, dimensions, material, and/or the number of coils inthe torsional part of the spring.

[0061]FIG. 13 illustrates another alternative embodiment of the markinginstrument 10, which is identical to the instrument 10 b of FIG. 12 inall respects not shown or described herein. Portions of the instrument10 c corresponding to portions of the instrument 10 b of FIG. 12 aredesignated by corresponding reference numerals followed by the letter c.

[0062] In actuality, the FIG. 13 embodiment is substantially identicalto that of FIG. 12, except for the shape of each spring 12 c, and isemployed in precisely the same manner. Thus, to deploy a marker element12 c, the mandrel 98 c is utilized to push the spring 12 c through thecenter lumen 56 c and out through the distal open end 90 c of the tube.As in the FIG. 12 embodiment, the marker element travels in thedirection of the arrow 100 c, until the attachment members 94 c and 96 cextend outwardly sufficiently to anchor themselves to the target tissue.Also, the FIG. 13 embodiment is similar to the FIG. 12 embodiment inthat the instrument may be repositioned to immediately deploy anothermarker element without re-loading, and marker elements may be deployedradially through a side port in tube 54 c (not shown), or any otherangle, to accommodate delivery through an existing instrument (i.e.cannula, needle, endoscope, laparoscope, or the like).

[0063]FIG. 14 shows still another alternative embodiment of the markinginstrument 10, which is also substantially identical to the instrument10 b of FIG. 12 in all respects not shown or described herein. Portionsof the instrument 10 d corresponding to portions of the instrument 10 bof FIG. 12 are designated by corresponding reference numerals followedby the letter d.

[0064] Again, the FIG. 14 embodiment is substantially identical to thoseof FIGS. 12 and 13, except for the shape of the marker element or spring12 d. A marker element 12 d is deployed preferably using a mandrel 98 dor the like to push the spring 12 d through the center lumen 56 d untilit exits through the open end 90 d of the tube. As in the FIGS. 12 and13 embodiments, the marker element travels in the direction of the arrow100 d, until the tips 102 d and 104 d extend outwardly sufficiently toanchor themselves to the target tissue.

[0065] In practice, a radiologist or other operator of the equipment canuse a marker shaped like marker 12 b, as shown in FIG. 12, during onebiopsy, then use a differently shaped marker, such as the marker 12 c inthe FIG. 13 embodiment, or the marker 12 d in the FIG. 14 embodiment,during a subsequent biopsy procedure. The differently shaped markerspermit the distinction between different biopsy procedures during futureimaging procedures, as well as between biopsy sites which may be closein proximity, thereby improving the information available to theradiologist and thus the ability to monitor or diagnose the patient'sfuture condition more precisely.

[0066]FIG. 15 illustrates yet another alternative embodiment of themarking instrument 10, which is also substantially identical to theinstrument 10 b of FIG. 12 in all respects not shown or describedherein. Portions of the instrument 10 e corresponding to portions of theinstrument 10 b of FIG. 12 are designated by corresponding referencenumerals followed by the letter e.

[0067] In this embodiment each marker element 12 e is deployed distallythrough the open distal region 90 e of the tube 54 e by a mandrel 98 e,much as in the previous embodiments shown in FIGS. 12, 13, and 14. Theprimary difference, however, between this embodiment and the previousembodiments is that, while the marker elements in the previousembodiments rely largely on the barbed nature of the spring to securethemselves in the tissue, in this embodiment, the springs are securedsimply because of their significant expansion upon exit from the tube.This embodiment particularly lends itself to marking the boundaries of abiopsy or other desired site by defining the perimeter of the site. Theexpansion of the spring 12 e causes the blunt edges 102 e and 104 e topress outwardly against the selected tissue, thereby wedging the springsecurely into position.

[0068] An advantage of this embodiment is that, because of the tightcompression of the springs 12 e within the tube 54 e, a larger number ofmarkers can be inserted therein simultaneously, thereby permitting thedeployment of more markers without having to pause and disengage tore-load.

[0069] Another advantage the FIG. 15 embodiment provides is the abilityto deploy springs adapted to expand to a number of different sizes allfrom the same lumen. Larger sized springs would require more coilswithin a given lumen than smaller sized springs (not shown).

[0070] It should be noted that the springs need not be limited to theconfiguration illustrated, but could include any spring of anyconfiguration which expands to secure its position. While stainlesssteel is presently preferred, any other biocompatible, implantable, andradiopaque material could be used alternatively. Also as in the previousembodiments, marker elements may be similarly deployed radially througha side port in tube 54 e (not shown), or any other angle, to accommodatedelivery through an existing instrument (i.e. cannula, needle,endoscope, laparoscope, or the like).

[0071] Still another alternative embodiment of the marking instrument 10is shown in FIG. 16. In this embodiment, the marking instrument 10 fcomprises a tube 54 f. Wire segments 106 of any desired length arepreloaded into the lumen 56 f, which runs along substantially the entirelength of the tube 54 f. Once the needle is properly positioned, themarker elements 12 f are deployed by pushing them out of the tip of theneedle, through the side exit port 108. A curved portion 110 of thelumen 56 f comprises a die portion, and is adapted to form the wiresegments 106 into helical marker elements 12 f as they passtherethrough, pushed by a mandrel (not shown) or other known means fromthe tip of the needle through the exit port 108. The nature of the curveor curves in the die portion 110 and preformed curves imparted into thewire segments determine the final shape (which resembles a partial orwhole helix) and dimensions of the marker element.

[0072] This embodiment is versatile in that it is capable ofcontinuously deploying any number of marker elements without thenecessity of re-loading, since all that is required is a continuous feedof wire segments into the proximal region of the tube 54 f. Furthermore,differently sized and shaped helixes may be delivered in the sameprocedure by utilizing marker wires of different diameters and/orpreformed curves, which approximate different helical shapes as theypass through the die portion. Thus, loading a plurality of differentsized wires into the needle yields a plurality of different shapedmarkers.

[0073] Of course, as with the previous embodiments, although stainlesssteel is presently preferred, many different types of biocompatible,implantable, and radiopaque materials could be utilized within the scopeof the invention. Also as in the previous embodiments, marker elementsmay be similarly deployed at different angles to accommodate deliverythrough an existing instrument (i.e. cannula, needle, endoscope,laparoscope, or the like).

[0074] Unlike previous embodiments, FIG. 16 preferably incorporates apiercing element 112 enabling this marker to be delivered without theaid of the positioning system described in FIGS. 1-3 for placement atthe tissue site. This embodiment could be used alone in conjunction witha commercially available stereotactic or other (i.e. ultrasonic)guidance system.

[0075] Though a number of different embodiments of the conceptualinvention have been described and shown, it is considered to be withinthe scope of the invention for the marking elements and deliveryinstruments to take on many other forms. For example, embolization coilslike that illustrated in FIG. 17 and designated with reference numeral12 g are well known in the medical field for placement into vessels suchas veins and arteries in order to block off fluid flow abnormalities(such as fistulas and arteriovenous malformations). These coils havebeen made of various materials, including stainless steel, platinum, andgold, and are wound into configuration similar to that of a light bulbfilament. They are generally placed into the body using a catheter ortrocar system. The inventors in the present application have discoveredthat such coils may indeed also be used as marker elements, forpermanent implantation in target tissue, in a manner similar to thatdescribed previously with respect to FIGS. 1-16.

[0076] Marker elements of many other materials and configurations may beused as well. For example, one such multi-appendaged jack-shaped marker12 h is illustrated in FIG. 18. Additionally, small beads 12 i (FIG. 19)of calcium carbonate or other radiodense materials, which are highlyvisible by mammographic imaging, could be deployed as marker elements.One such application would be to place a plurality of such beads orpellets (each having a diameter of about 500μ) around the entirety of abreast lesion prior to the extraction procedure, which would then serveas guides to ensure that all of the margins had been removed. Duringsubsequent imaging procedures, they would function to denote thelocation of the previous biopsy for reference purposes.

[0077] Referring now to FIG. 20, yet another alternative marker element12 j, which is of a woven construction, is illustrated. Other suchmarker materials may include adhesives and epoxies which would beinjected at the biopsy site. Biodegradable polymers and other plasticscould also be used, as long as they are biocompatible, implantable, andvisible using an imaging system.

[0078] While this invention has been described with respect to variousspecific examples and embodiments, it is to be understood that theinvention is not limited thereto and that it can be variously practicedwithin the scope of the following claims.

What is claimed is:
 1. A device for marking a particular tissue areawithin a human body to identify said particular tissue area for a laterdiagnostic or therapeutic procedure, comprising: a discrete markerelement; an apparatus for remotely delivering said marker element fromoutside the human body to the particular tissue area using an aidedvisualization device; said apparatus including a member having a distalregion and a proximal region, said member being adapted to extendthrough said human body and to receive a deployment actuator connectorwhich extends axially therealong, said connector comprising a distalportion which extends distally of the member and a proximal portionwhich extends proximally of the member, the proximal portion beingattached to a deployment actuator and the distal portion being attachedto said marker element, wherein actuation of said deployment actuator istransmitted from the proximal portion of the connector to the distalportion thereof to cause release and deployment of said marker element;a predetermined failure point in the distal region of said deploymentactuator connector, wherein once the distal region of said member ispositioned at said selected tissue location, the deployment actuator maybe actuated to pull the marker element against the distal region of saidmember, said member distal region being adapted to function as a formingdie to cause the marker element to bend until it encounters a stopdesigned into said member distal region, such that the marker element isreconfigured to a desired shape, the proximal portion of said connectorbeing adapted to be severed from the distal portion at saidpredetermined failure point upon the further actuation of saiddeployment actuator after abutment of the marker element against saidstop, thereby releasing and implanting said marker element; and saidapparatus further comprising a cutting tip for piercing said human body;wherein said marker element is adapted to become entirely implanted insaid particular tissue area, such that no part of the marker elementextends outside of said body.
 15. A device as recited in claim 1, andfurther comprising a plurality of marker elements adapted to assume aplurality of shapes, wherein each shape denotes a different selectedtissue location or event.
 16. A device as recited in claim 1, whereinsaid device is adapted to be employed in combination with a medicalinstrument which transports said device to said selected tissue locationresponsive to positional control by a guidance system.
 17. A device formarking a particular tissue area within a human body to identify andparticular tissue area for a later diagnostic or therapeutic procedure,comprising: a discrete marker element; an apparatus for remotelydelivering said marker element from outside the human body to theparticular tissue area, using an aided visualization device; saidapparatus including a member having a distal region and a proximalregion, said member being adapted to extend through said human body andto receive a deployment actuator connector which extends axiallytherealong, said connector comprising a distal portion which extendsdistally of the member and a proximal portion which extends proximallyof the member, the proximal portion being attached to a deploymentactuator and the distal portion being attached to said marker element,wherein actuation of said deployment actuator is transmitted from theproximal portion of the connector to the distal portion thereof to causerelease and deployment of said marker element: wherein said device isadapted to be employed in combination with a medical instrument whichtransports said device to said selected tissue location responsive topositional control by a guidance system; said medical instrument drawinga vacuum to isolate and retain tissue at the selected location and saidmarking device being adapted to deploy said marker element into saidretained tissue.
 35. A device as recited in claim 1, wherein the markerelement has a width of less than 0.1 inches.
 36. A device as recited inclaim 1, wherein the marker element has a width at its distal end withina range of 0.035-0.045 inches.
 37. A device as recited in claim 1,wherein the particular tissue area comprises a lesion within the body,and no part of the marker element extends outside of said lesion.
 43. Adevice as recited in claim 38, wherein said device is adapted to beemployed in combination with a medical instrument which transports saiddevice to said selected tissue location responsive to positional controlby a guidance system.
 44. A device for marking a particular tissue areawithin a human body to identify said particular tissue area from a laterdiagnostic or therapeutic procedure, comprising: a discrete markerelement; and an apparatus for remotely delivering said marker elementfrom outside the human body to the particular tissue area, using anaided visualization device, the apparatus including a member having adistal region and a proximal region, said member being adapted to extendinto said human body, wherein said distal region is adapted to retainand deploy said marker element and said proximal region is linked tosaid distal region, so that predetermined marker deployment functionsmay be communicated from said proximal region to said distal region;said member being adapted to receive a deployment actuator connectorwhich extends axially therealong, said connector comprising a distalportion which extends distally of the member and a proximal portionwhich extends proximally of the member, said proximal portion beingattached to a deployment actuator and said distal portion being attachedto said marker element, wherein actuation of said deployment actuator istransmitted from the proximal portion of the connector to the distalportion thereof to cause release and deployment of said marker element;a predetermined failure point in the distal region of said deploymentactuator connector, wherein once the distal region of said member ispositioned at said selected tissue location, the deployment actuator maybe actuated to pull the marker element against the distal region of saidmember, said member distal region being adapted to function as a formingdie to cause the marker element to bend until it encounters a stopdesigned into said member distal region, such that the marker element isreconfigured to a desired shape, the proximal portion of said connectingmeans being adapted to be severed from the distal portion at saidpredetermined failure point upon the further actuation of saiddeployment actuator after abutment of the marker element against saidstop, thereby releasing and implanting said marker element; wherein saidmarker element is adapted to become entirely implanted in saidparticular tissue area, such that no part of the marker element extendsoutside of said body.
 45. A device as recited in claim 16, wherein saidmedical instrument draws a vacuum to isolate and retain tissue at theselected location and said marking device is adapted to deploy saidmarker element into said retained tissue.